As a heat exchange device of this type, Patent Literature 1 discloses a heat exchange device including a first heat exchanger, and a second heat exchanger which has an effective length shorter than the effective length of the first heat exchanger, the heat exchangers being arranged adjacent to each other so as to face each other, the heat exchange device being configured such that an L-shaped first mounting plate bent to the ventilation surface on the front surface side or the rear surface side of the heat-dissipating tins of the first heat exchanger is provided on the side surface of the first heat exchanger, such that an L-shaped second mounting plate, whose portion on the side of the first heat exchanger is bent in the projecting direction of refrigerant tubes, is provided on the side surface of the second heat exchanger, the side surface being on the same side as the first mounting plate, such that an engagement hole and an engagement claw, which are respectively provided at portions where both the mounting plates face each other (portions where both the mounting plates face each other in the ventilation direction), are engaged with each other, and thereby the second heat exchanger is positioned at a different level retreated from the side surface of the first heat exchanger.
Further, Patent Literature 2 discloses an air conditioner in which, in an heat exchanger including a number of heat-dissipating fins arranged in parallel at equal intervals, and refrigerant tubes arranged perpendicularly to the heat-dissipating fins, end portions of the refrigerant tubes are connected to each other by hair-pin shaped (U-shaped) connection tubes, and a side plate made of a steel plate is provided on the side portion of the heat exchanger, and in which the heat exchanger is fixed to a cabinet of the air conditioner and a partition plate in the cabinet by screwing, through through-holes, screws into screw holes of the upper portion of the side plate and the lower portion of the side plate forming the side plate (see paragraph 0017 in the specification of Patent Literature 2).